Single-joint extensible device and bridge

The invention relates to building extensible devices and provides a single-joint extensible device which comprises two side beams positioned on two sides of an extensible joint and a waterproof rubber strip clamped between the side beams and stretching over the extensible joint. The waterproof rubber strip is sequentially bent along a stretching-over direction, and two ends of the waterproof rubber strip are respectively in fitted connection with opposite surfaces between the side beams. The invention further provides a bridge which comprises the extensible device. The side beams are connected by the waterproof glue strip which is sequentially bent, so that the waterproof rubber strip is enabled to have good extensible performance along the stretching-over direction, and deformation requirements of the extensible joint can be met; gravel accumulated on the waterproof rubber strip can be extruded, and deslagging and dedusting effect can be realized, so that service life of the extensible device on the bridge c